xpdrainage can import surface data from LandXML files.
LandXML is a non-proprietary data standard on the Extensible Markup Language (XML) format. LandXML files contain civil/survey data elements such as points, profiles, surfaces, and many others. The format is often used to interchange design information with 3D design and engineering software packages, and for archiving data.
Further information about the LandXML format can be found at http://www.landxmlproject.org/.